ABS

IMPORTANT NOTICE: Ultimately, the safety of motorcycle riders and their passengers is their own responsibility. Nothing presented in the column supersedes, negates or relieves a motorcyclist and/or passenger from assumption of personal responsibility for their actions and safety.

Doug Westly | Safety Editor

absJust last month I had a discussion with my nephew, who is looking to get back into motorcycling after a layoff of a couple of years from the sport. He visited us while we were at the track, getting in some laps for the day. After discussing potential bike options (he is a very experienced motorcyclist), he startled me with “So, do you think ABS is worth it?” To say I was stunned was an understatement. As a rider with probably 20 years under his belt, I had just assumed he would understand the safety factor that ABS brings to our sport. In retrospect, you know what they say about assumptions. Anyway, we had a long discussion about ABS and in the end, he was a convert.

That discussion has prompted this column. Perhaps there are other experienced riders out there that still don’t understand the additional safety element ABS adds to our street riding (We’ll limit our discussion to the street here. Off-road riding presents an entirely different set of factors in terms of motorcycle ABS and other electronic/mechanical safety systems). With that in mind, I’d like to offer up the following thoughts about ABS, not only as a motorcycling enthusiast, but also stemming from one of my former career jobs as a US Government advanced tactical driving instructor.

Let’s do the basics of ABS quickly. Motorcycle ABS, or “Anti-lock Brake System” is designed to prevent either wheel from locking up under varying circumstances involving application of the brakes in differing traction environments. Remember that when tires are sliding and not rotating, you have neither control or stopping in process. You are basically a sliding brick on the road surface at that point. Theoretically with ABS, no matter how hard you apply the brakes, or how tenuous the traction between tire and road surface, the system will not allow the tire to continuously lock and slide. I say continuously, as most systems today use an electronic/hydraulic or mechanical/hydraulic process that only activates when the wheel actually stops rotating, reducing brake pad pressures to allow the wheel to start rotating again. The best modern systems work so fast that you almost can’t feel them work, but nevertheless they still depend on detection of wheel rotation stoppage to activate.

So back to the question posed by my nephew, “So, do you think ABS is worth it?” There are some riders who will argue that with good technique, you can actually stop faster without ABS. Technically this is true. There is a technique called “Threshold Braking”, wherein you bring the braking force on the wheels to the maximum available limits, without locking the tires up. You then hold that braking force (you can actually increase the force as you slow down) at maximum limits until the vehicle stops. The technique works in both cars and on motorcycles, and theoretically is faster than ABS, as the tires never stop rolling at all. HOWEVER, for the vast majority of either riders or drivers, this technique presupposes the following conditions and underlying reasons:

1. A good traction environment. You must have dry pavement without traction-reducing factors such as sand, potholes, rough surface, etc. Wet or slick pavement causes a significant reduction in traction, making braking “feel” almost impossible for the Threshold Braking technique.

2. You must have practiced this technique on a regular basis, with your tires in good condition, at a routine, constant pressure and braking system in good condition. Also, your practice needs to be performed in the same conditions as typical riding under which the Threshold Braking could be utilized, i.e. riding two-up, or maybe fully loaded for a long trip. Total GVW plays a big role in needed braking forces. You can’t practice the technique under one set
of circumstances, and then expect to duplicate those results with motorcycle systems or conditions which vary from the practice environment.

3. You can’t be caught unaware of the need to implement the Threshold Braking technique. When caught by surprise, riders and drivers both undergo biophysiological changes, which accelerate
internal chemical stimulation of muscles, causing immediate and usually overreaction of internal motor control input, and loss of fine muscle control, both critical to successful Threshold Braking.

The bottom line is that in a crash situation, the chances are that
the rider (or driver) will just grab for all the brakes they can get, regardless of their experience and training. Add unknown or reduced traction environments to this mix and the chance that the rider will successfully execute Threshold Braking to avoid the crash is almost non-existent. It just doesn’t happen in the real world for 99% of riders.

This is why ABS is such a valuable safety system (and dynamic traction control, for that matter). ABS doesn’t depend on the traction environment. It will work under any traction situation. Granted, stopping distances will still increase given proportionally reduced traction, but ABS will still keep the tires rolling. The one exception to to this is in extreme low traction environments such as snow, ice or oil-slick surfaces, particularly in corners, where ANY loss of traction, even the momentary lock-up of an ABS-equipped wheel, could cause a fall. Riders need to understand that even the best systems have limitations.

ABS doesn’t require practice. It will  work each time, every time. It doesn’t care if you have the bike loaded, you are two-up, or the tires aren’t at the perfect pressure. Also, ABS doesn’t get caught by surprise. When the crash factors start to envelope you, ABS doesn’t experience the flood of dopamine, cortisol, adrenaline and all those other chemicals that flood instantaneously into your bloodstream and muscles. ABS can still execute the braking process, no matter how ham-handed the rider gets due to the surprise and excitement.

“So, do you think ABS is worth it?” I suggest that you only have to need it one time for the system to pay for itself. As for my wife
and I, we don’t and will not own a modern motorcycle without ABS.

Leave a Reply